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IWM in a HT Canola World Manitoba Agronomists – Dec. 15, 2010
IWM in a HT Canola World
Manitoba Agronomists – Dec. 15, 2010
From the Past… • “Time and again our best efforts to improve Nature have foundered
on some factor we failed to consider” – Allan Savory Holistic
Resource Management (1988)
• “Repeating a successful practice is not a problem in the world of
assembly lines and machines, where all „genotypes‟ are defined.
But living systems with inherently high levels of variation and
diversity rapidly adapt to repeated practices. Adaptation is more
difficult when practices are diverse.” – Harker Weed Sci. 52:183
(2004)
• “In the U.S. we are putting 150 Million Pounds of Glyphosate on 100
Million Acres of Cropland every year. What do you think is going to
happen?” – John Wilcut, NC State (2007)
GR Palmer Amaranth in Tennessee - Let‟s talk “Selection Pressure”
• 4 fields of continuous cotton for ≥ 6 yr (Steckel et al. 2008 Weed Technol. 22:119-123)
• Herbicide regime
– Preseed Burn-off: Gly (0.84 kg/ha) + dicamba
– 1st In-crop: Gly (0.84 kg/ha) – early POST
– 2nd In-crop: Gly (0.84 kg/ha) – prior to 5 leaves
– 3rd In-crop: Gly (0.84 kg/ha) + diuron – POST-directed (PD)
– Some years – 4th In-crop: Gly (0.84 kg/ha) + diuron PD
• All 4 fields with 2x to 4x rate Palmer amaranth resistance to glyphosate
• Palmer amaranth populations in Georgia are confirmed resistant to 12x rates of glyphosate (Culpepper et al. 2006 – Weed Sci. 54:620-626) – much more in 2010!
Amaranthus palmeri
Palmer Amaranth
Amaranthus tuberculatus (syn. rudis)
Tall Waterhemp
Kochia scoparia
Kochia
Ambrosia artemisiifolia
Common Ragweed
Conyza bonariensis
Hairy Fleabane Eleusine indica
Goosegrass
Ambrosia trifida
Giant Ragweed
Conyza canadensis
Horseweed
Lolium rigidum
Rigid Ryegrass
Poa annua
Annual Bluegrass
Sorghum halepense
Johnsongrass
Lolium multiflorum
Italian Ryegrass
Glyphosate- Resistant Weeds – USA December 13, 2010 – adapted from: www.weedscience.org
1st – Real IWM Ehler (2006) – Pest Manag. Sci. 62:787-789
• Is NOT tank-mixing herbicides (the “other IWM”)
• Is NOT rotating herbicide modes of action (the
“other IWM”)
• Is NOT applying PRE herbicides before POST
herbicides (the “other IWM”)
• Is using non-herbicide tools in addition to
herbicides (Real IWM)
HT Canola IWM…
• Careful seeding & fertilizing…
• Using competitive crop cultivars…
• Early TWR…
• Crop diversity & rotation…
• Combining optimal agronomics…
• Careful harvesting…
Careful Seeding…
Lacombe – 2007
Emergence: plants/m2
87
79
72
61
89
80
64
60
40
50
60
70
80
90
100
4 mph, 1cm 4 mph, 4 cm 7 mph, 1cm 7 mph, 4 cm
pla
nts
/ m
2
Hybrid
OP
LSD (0.05) = 18
Seeding Rate: 150 seeds/m2
50% emergence
Hybrid = 71-45 RR OP = 34-65 RR
3465 RR (OP)
4 mph – 1 cm
7 mph – 1 cm
4 mph – 4 cm
7 mph – 4 cm
7145 RR (Hy)
4 mph – 1 cm 4 mph – 4 cm
7 mph – 1 cm 7 mph – 4 cm
Canola Emergence & IWM?
Hybrid
4 mph
1 cm
Hybrid
4 mph
4 cm
A 2nd Herbicide
Application is
much more likely
to be needed
here…
June 7 (April seeded)
IWM is
careful seeding
NOT
IWM
Careful Fertilizing During Seeding
Barley Cover - June 20 , 2002
(seeding rate = 300 seeds/m2, seeding date = May 20)
Trt 13; Plot 113 22%
90 kg/ha N in seed row
Trt 17; Plot 117 78%
90 kg/ha N pre plant band
Wild Oat Response to N placement
- 90 kg/ha N in seed row
See also Figure 1 - O‟Donovan et al. (2008) Crop Sci. 48:1569–1574
22% vs. 78% Cover 967 vs. 192 kg/ha wo biomass
June 20 July 30
Poor N placement increased wild oat biomass 5 fold
Some weeds that don‟t
like a crop canopy…
Arenaria serpyllifolia
Thyme-leaved sandwort
(Caryophyllaceae)
Cerastium holosteoides
Moused-eared
chickweed
(Caryophyllaceae)
Veronica arvensis
Corn speedwell
(Scrophulariaceae)
Seed Germination (%) – 3 Light Qualities
Species
Common
name
Light
Dark
Red-light
depleted*
Arenaria
serpyllifolia Thyme-leaved
sandwort 95 65 1
Cerastium
holosteoides Mouse-eared
chickweed 94 93 27
Veronica
arvensis Corn speedwell 94 89 1
King. 1975. New Phytol. 75:87-90
*Petri dishes wrapped in Tilia x europaea leaves (simulate a crop canopy)
Dandelion Germination
- with 2 light sources
64
86 87
0 0 2 0
20
40
60
80
100
4 8 12
%
Days after Exposure
Diffuse Light
Plant Canopies
T. Górski. 1975. Germination of seeds in the shadow of plants. Physiol. Plant 34:342-346
- rhubarb, rye, barley, dense currant, and wild shrubs canopies
Falcon Phoenix
Semi-leafless –‟Carrera‟
Leafy –‟Grande‟
Cultivar Differences…
Both plots treated with
- imazethapyr / imazamox
at 3-4 Leaf pairs
See Harker et al. (2008) Weed
Technol. 22:124–131
Crop Competition Study…
• Rapid crop growth limits resource availability to weeds
• Strong crop competition minimizes herbicide inputs
and enhances herbicide performance (IWM)
• Hybrid canolas compete more strongly with weeds
than open pollinated cultivars (Harker et al. 2003,
Zand & Beckie 2002) and could rival barley as a
competitor
• OBJECTIVE: Determine species/cultivars and the
environmental conditions that favor rapid resource
capture and strong crop competition with weeds
Materials & Methods
• Direct Seeding Experiment (Conserva-Pak) at 4 AAFC
sites (Lacombe, Lethbridge, Beaverlodge, Scott) in 2006-
2008 and at U of S (Saskatoon) in 2007-2008
• Several different types of spring canola (seed rate 150
seeds/m2) were compared to the spring cereals (seed
rate 300 seeds/m2) barley, wheat, triticale and rye.
• Cultivated oat was seeded across all plots to simulate a
weed infestation and to ensure relatively uniform “weed”
densities across plots.
• The experiment was designed as a randomized complete
block with 4 replications. Plot size = 3.7 x 15 m
Species / Varieties
1. „45H21‟ RR hybrid canola (Brassica napus)
2. „InVigor 5020‟ LL hybrid canola (B. napus)
3. „45H72‟ CF hybrid canola (B. napus)
4. „3465‟ RR OP canola (B. napus)
5. „AC Excel‟ OP canola (B. napus)
6. „Westar‟ OP canola (B. napus)
7. „ACS-C7‟ synthetic canola (B. rapa)
8. „Vivar‟ spring barley (Hordeum vulgare)
9. „AC Metcalfe‟ spring barley (H. vulgare)
10. „Superb‟ HRS spring wheat (Triticum aestivum)
11. „AC Foremost‟ CPS spring wheat (T. aestivum)
12. „Pronghorn‟ spring triticale (X Triticosecale)
13. „Gazelle‟ spring rye (Secale cereale)
Oat BM at Maturity versus
Crop BM at Maturity
Lethbridge y = -0.3816x + 3460.7
R2 = 0.6974
0
500
1000
1500
2000
2500
3000
3500
4000
0 1000 2000 3000 4000 5000 6000 7000 8000
Crop Biomass
Oat
Bio
mass
Oat Biomass at Maturity – Scott
5600
4947
4259
3895
3819
3415
3246
3190
3119
2477
2197
1771
1765
1755
0 1000 2000 3000 4000 5000 6000
No Crop
Canola Synthetic - ACS-C7
Canola OP - Excel
Canola OP - Westar
Canola OP 3465 - RR
Canola Hybrid 45H21 - RR
Canola Hybrid InVigor 5020 - LL
Canola Hybrid 45H72 - CF
CPS Wheat - Foremost
Triticale - Pronghorn
HRS Wheat - Superb
Barley - Vivar
Barley - Metcalfe
Rye - Gazelle
LSD = 805
(kg/ha)
Oat Biomass at Maturity – Lacombe
2899
2024
2003
1956
1867
1818
1801
1733
1636
1501
1479
1455
1108
1081
0 500 1000 1500 2000 2500 3000
No Crop
CPS Wheat - Foremost
Canola Synthetic - ACS-C7
Barley - Metcalfe
HRS Wheat - Superb
Canola OP 3465 - RR
Triticale - Pronghorn
Canola OP - Westar
Canola OP - Excel
Canola Hybrid 45H72 - CF
Barley - Vivar
Rye - Gazelle
Canola Hybrid 45H21 - RR
Canola Hybrid InVigor 5020 - LL
LSD = 692
(kg/ha)
Crop Competition Rank – Top 5
– Least Monocot Weed biomass @ Maturity
Bea 2007 (dry) → Lac 2007 (wet)
Bea 2007 ~Sco 2007 Lac 2007
Rank g m-2 g m-2 g m-2
1 Bar-Met 1149 Bar-Met 1954 Bar-Met 3538
2 Bar-Viv 1290 Rye-Gaz 2238 Rye-Gaz 4001
3 Rye-Gaz 1331 Bar-Viv 2245 Bar-Viv 4171
4 Tri-Pro 1444 Tri-Pro 2588 Tri-Pro 4967
5 Hyb-LL 1500 Hyb-LL 2812 Whe-HRS 5508
Crop Competition Rank – Top 5
– Least Dicot Weed biomass @ Maturity
Sas 2008 (warm) → Bea 2007 (cool)
Sas 2008 ~Sco 2007 Bea 2007
Rank g m-2 g m-2 g m-2
1 Bar-Met 5 Bar-Viv 86 Hyb-CF 316
2 Bar-Viv 5 Bar-Met 92 Hyb-LL 324
3 Rye-Gaz 13 Hyb-LL 96 Hyb-RR 343
4 Hyb-LL 18 Rye-Gaz 113 OP-Exc 411
5 Tri-Pro 20 Hyb-RR 148 Rye-Gaz 566
Lacombe Plots - “Cool/Moist” Site-Year – July 24, 2006
‘Vivar’ Barley
Lacombe Plots - “Cool/Moist” Site-Year – July 24, 2006
‘45H21’ RR Canola Hybrid
IWM is planting competitive cultivars
Early TWR
Field-Scale Confirmation
CCC Agronomists
Time of Weed Removal
- Canola Yield (bu/ac)
3734
30
0
10
20
30
40
1 to 2 3 to 5 6 to 7
Canola Leaf Stage
Means of 10 western Canada locations
CCC Agronomists - large-scale plots (9 x 122 m) in grower fields
Harker et al. 2008. Weed Technol. 22:747-749.
Waiting to Spray…
$ lost / half section
6533
16985
13748
35744
0 10000 20000 30000 40000
3-5 Leaf
6-7 Leaf
$ Lost
$650/t
$250/t
Waiting for the last Flush?
You may have just flushed your yield!
IWM is early TWR
Combining Optimal Agronomics
ICM Crop Health - Factors
• 3 Locations: Lacombe, Beaverlodge, Brandon
• Rotation – Continuous Barley or B-C-B-P
• Varieties/Cultivars
– Short („Peregrine‟ or „Vivar‟)
– Tall („AC Bacon‟ or „AC Lacombe‟)
• Seeding Rate – 1X or 2X (200 or 400 seeds/m2)
• Herbicide Rate – ¼, ½, or 1X (ACCase or ALS)
• Treatments applied to same plots year after year
– cumulative treatment effects
Year 5
Wild Oat BM – Maturity – ¼ X Rate
– 2005
4530
18751966
614
1344
44954265
0
1000
2000
3000
4000
5000
Continuous Rotation
kg
/ha
Short 200
Tall 200
Short 400
Tall 400
LSD (0.05) = 614
200 to 400 = 3X reduction
Short to Tall = 2X reduction
Both factors = 8X reduction
All factors = 70X reduction
Harker et al. 2009. Weed Sci. 57:326-337
1 + 1 + 1 > 3
- Short
- 200 seeds
- B-B-B-B-B
- ¼ Rate
Tall
400 seeds
B-C-B-P-B
¼ Rate
August 23, 2005
IWM is combining optimal agronomics
IWM is More Rotational Diversity
2010 2011 2012 2013 2014
RR Canola Wheat LL Canola Wheat RR Canola
LL Canola Barley LL Canola Barley RR Canola
LL Canola Barley Peas Wheat RR Canola
LL Canola Early Silage Early Silage Winter Wheat RR Canola
LL Canola Early Silage Winter Trit. Early Silage RR Canola
LL Canola Fall Rye Peas Winter Trit. RR Canola
LL Canola Early Silage Peas Winter Trit. RR Canola
LL Canola Alfalfa Alfalfa Alfalfa RR Canola
8 Locations: 6 Western Canada, Ontario, Quebec
• How much is left on the ground?
• How much goes in and then out of the combine?
• How many seeds will volunteer to be a weed?
• IWM is careful harvesting!
Vacuuming
can be fun!
Seed # Losses – 2010 – Total Losses in Swathed Fields
0
1000
2000
3000
4000
5000
6000
7000
8000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
# s
eed
s/m
2
Field #
Bushel Losses – 2010 – Total Losses in Swathed Fields
0.0
1.0
2.0
3.0
4.0
5.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
bu
/ac
Field #
Seed # Losses – Straight-Cut
0
2000
4000
6000
8000
10000
12000
1 2 3 4 5 6 7
# s
eed
s/m
2
Field #
Bushel Losses – Straight-Cut
0
1
2
3
4
5
6
1 2 3 4 5 6 7
bu
/ac
Field #
Summary
• Using different herbicides is NOT IWM
• Seeding and fertilizing carefully is IWM
• Growing competitive cultivars is IWM
• Crop rotation is IWM
• Combining optimal agronomics is IWM
• Harvesting carefully is IWM
• Even HT canola hybrids benefit from IWM!
